# man(1) completion                                        -*- shell-script -*-

_man()
{
    local cur prev words cword split
    _init_completion -s -n : || return

    local comprsuffix=".@([glx]z|bz2|lzma|Z)"
    local manext="@([0-9lnp]|[0-9][px]|man|3?(gl|pm))?($comprsuffix)"
    local mansect="@([0-9lnp]|[0-9][px]|3?(gl|pm))"

    case $prev in
        --config-file | -!(-*)C)
            _filedir conf
            return
            ;;
        --local-file | -!(-*)l)
            _filedir "$manext"
            return
            ;;
        --manpath | -!(-*)M)
            _filedir -d
            return
            ;;
        --sections | -!(-*)[Ss])
            _comp_delimited : -W '{1..9}'
            return
            ;;
        --pager | -!(-*)P)
            compopt -o filenames
            COMPREPLY=($(compgen -c -- "$cur"))
            return
            ;;
        --preprocessor | -!(-*)p)
            COMPREPLY=($(compgen -W 'e p t g r v' -- "$cur"))
            return
            ;;
        --locale | --systems | --extension | --prompt | --recode | --encoding | \
            -!(-*)[LmerRE])
            return
            ;;
    esac

    $split && return

    if [[ $cur == -* ]]; then
        COMPREPLY=($(
            compgen -W '$(_parse_help "$1" -h || _parse_usage "$1")' -- "$cur"
        ))
        [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
        return
    fi

    # file based completion if parameter looks like a path
    if [[ $cur == @(*/|[.~])* ]]; then
        _filedir "$manext"
        return
    fi

    local manpath=$(manpath 2>/dev/null || command man -w 2>/dev/null)
    if [[ -z $manpath ]]; then
        # Note: Both "manpath" and "man -w" may be unavailable, in
        # which case we determine the man paths based on the
        # environment variable MANPATH.
        manpath=:${MANPATH-}:
        # Note: An empty path (represented by two consecutive colons
        # or a preceding/trailing colon) represents the system man
        # paths.
        manpath=${manpath//::/':/usr/share/man:/usr/local/share/man:'}
        manpath=${manpath:1:-1}
    fi

    # determine manual section to search
    local sect
    # shellcheck disable=SC2053
    [[ $prev == $mansect ]] && sect=$prev || sect='*'

    _expand || return

    manpath=$manpath:
    if [[ -n $cur ]]; then
        manpath="${manpath//://*man$sect/$cur* } ${manpath//://*cat$sect/$cur* }"
    else
        manpath="${manpath//://*man$sect/ } ${manpath//://*cat$sect/ }"
    fi

    local IFS=$' \t\n' reset=$(shopt -p failglob)
    shopt -u failglob
    # redirect stderr for when path doesn't exist
    COMPREPLY=($(eval command ls "$manpath" 2>/dev/null))
    $reset

    if ((${#COMPREPLY[@]} != 0)); then
        # weed out directory path names and paths to man pages
        COMPREPLY=(${COMPREPLY[@]##*/?(:)})
        # strip suffix from man pages
        ((${#COMPREPLY[@]})) &&
            COMPREPLY=(${COMPREPLY[@]%$comprsuffix})
        ((${#COMPREPLY[@]})) &&
            COMPREPLY=($(compgen -W '"${COMPREPLY[@]%.*}"' -- "${cur//\\\\/}"))
    fi

    # shellcheck disable=SC2053
    if [[ $prev != $mansect ]]; then
        # File based completion for the rest, prepending ./ if needed
        # (man 1.6f needs that for man pages in current dir)
        local i start=${#COMPREPLY[@]}
        _filedir "$manext"
        for ((i = start; i < ${#COMPREPLY[@]}; i++)); do
            [[ ${COMPREPLY[i]} == */* ]] || COMPREPLY[i]=./${COMPREPLY[i]}
        done
    fi

    __ltrim_colon_completions "$cur"
} &&
    complete -F _man man apropos whatis

# ex: filetype=sh
